@Durin's Bane - re: AKL - I usually do this trip each year and I always clear immigration, exit the airport and sit on one of the benches in the departures area and watch Netflix until the QF check in opens next morning.
From memory this is how it used to go - deplane, clear immigration, go thru the arrivals doorway and either - go up again the escalators, which were the international security is, take a bench hostage and settle down OR stay downstairs, walk to the end of the terminal (this is where QF check in is) and there will be some empty benches around that area and settle down for the night, wait until QF check in opens next AM. They usually open around the 0430 mark and the lounge opens around 0500 mark? Take a shower, meal and back on the next service back into AU
I won't be surprised if you find some fellow *travelers* who are also doing the status runs, scanning for empty benches
I found at least 2 AFF'ers who were on their Status Runs to AKL seated next to me in J in 2020, just before borders were shut